Given: Length of platforms are 110 m and 205 m
The train crosses the first platform in 13.5 seconds
The train crosses the second platform in 18.25 seconds
Formula Used: Distance = Speed × Time
Calculation: Let the length of the train is 'x' meters and the speed of the train is 's' m/s.
When it crosses the first platform,
=13.5 ⇒ x + 110 = 13.5s
⇒ x = 13.5s – 110 ----(1)
And when it crosses the second platform,
=18.25 ⇒ x + 205 = 18.25s
From equation (1), we get
13.5s – 110 + 205 = 18.25s
⇒ 4.75s = 95
⇒s= ⇒ s = 20 m/s = 20 ×
km/h = 72 km/h
∴ Speed of the train is 72 km/h.